This invention relates to the field of nuclear magnetic resonance (NMR) spectroscopy devices, and more particularly to one or more small scale NMR spectroscopic apparatuses and methods of using same.
Nuclear magnetic resonance, or NMR as it is abbreviated by scientists, is a phenomenon which occurs when the nuclei of certain atoms are immersed in a static magnetic field and exposed to a second oscillating magnetic field. Some nuclei experience this phenomenon, and others do not, dependent upon whether they possess a property called spin. NMR is based on the nuclear magnetic properties of certain elements and isotopes of those elements. It is a fundamental law of quantum mechanics that nuclei with nonzero spin will have a magnetic dipole and will thus interact with electromagnetic radiation. The presence or absence of a spin and the nature of the spin is expressed in terms of the spin quantum number (I) of the nucleus, which may be either 0, ½, or integer multiples of ½. In a uniform magnetic field, a nucleus having a spin quantum number of ½ may assume two orientations relative to the applied magnetic field. The two orientations have different energies, so that it is possible to induce a nuclear transition by applying electromagnetic radiation of the appropriate frequency. This nuclear transition, known as resonance, is thus brought on when the correct combination of magnetic field strength and exciting frequency characteristic of the nuclei of interest are applied.
Spectroscopy is the study of the interaction of electromagnetic radiation with matter. Nuclear magnetic resonance spectroscopy is the use of the NMR phenomenon to study physical, chemical, and biological properties of matter. NMR spectroscopy is one of the principal techniques used to obtain physical, chemical, electronic and/or structural information about molecules due to at least one of the chemical shift, the Zeeman effect, and the Knight shift effect on the resonant frequencies of the nuclei present in the sample. It is a powerful technique that can provide detailed information on the topology, dynamics and/or three-dimensional structure of molecules in one or more liquid and/or gaseous solution(s) and a solid state thereof. Over the past fifty years, NMR spectroscopy has become the preeminent technique that can be used for structural and/or quantitative analysis of a compound in a mixture, especially an organic one. Of all the spectroscopic methods, NMR spectroscopy is the only one for which a complete analysis and interpretation of the entire spectrum is normally expected. Although larger amounts of a sample are needed than for mass spectroscopy, NMR spectroscopy is non-destructive, and with modern instruments, good data may be obtained from samples weighing less than a milligram. One of the most important groups analytically has a nuclear spin quantum number of ½ because the group includes 1H presented in one or many compounds of interest. Because all nuclei have unique resonances, e.g., approximately 100 megahertz in a 2.35 Tesla field for protons, 1H NMR will only detect compounds having protons. Moreover, because the exact frequency at which a proton resonates within this range is related to its chemical environment, the 1H NMR signal of protons of one compound can generally be distinguished from another, and an integrated intensity of the signal is directly proportional to the amount of the compound of interest. The position of the resonance signal is characterized by its frequency, i.e., the chemical shift, which is usually expressed on a ppm scale relative to the resonance frequency of some standard compound.